1. Field Of The Invention
The present invention relates to a closed refrigeration system with valved fittings having a plurality of capped threaded stems extending from two parallel elongated manifolds intersected by a transverse manifold, at a 90 degree angle, upstream from the liquid shut off valve and shut off seat of the main flow valve to create a by pass connection and, also, to a method for servicing, installing, testing or vacuuming the system and/or removing, storing or adding fluid refrigerant to the system.
The term "Refrigerating System", as used herein, relates to the current state-of-the-art systems that use compressible evaporative refrigerants to transfer heat, e.g., refrigerators, freezers and air conditioning units, including residential, commercial, automotive and other mobile types.
The maintenance of such systems requires that the refrigerant system be tested and additional refrigerant fluid be added thereto if the fluid contained in the system is below a predetermined pressure. Also, the refrigerant must sometimes be removed from the system in order to effect repairs and the system must then be recharged.
Installation, maintenance, testing and/or repairs of such pressurized systems and the infusion of additional refrigerant fluids to said systems require that a valve device or means be installed in the system to accomplish such work without the evaporative fluid in the enclosed space escaping from the system in order that the work can be performed in a safe, economical, efficient and environmentally protective manner.
The present invention, the "Hubbell-Double Valve", provides a means to accomplish the aforesaid purposes that is simple to install in said "Refrigerating System" and is simple to construct and inexpensive to manufacture.
2. Description Of Prior Art
Many refrigeration and air conditioning systems, especially residential and mobile, have threaded fittings in which a threaded check valve core is installed to provide access to the system. Such threaded check valves are of the type commonly used in automobile tire valve stems and are often referred to as "Schrader" type (depressing) valve cores. Most have no shut off valves, thus allowing a loss of refrigerant when connecting or disconnecting charging hoses, which results in unsafe, wasteful and harmful emissions into the atmosphere (causing Ozone depletion) in addition to unbalanced refrigerant charges in the system which causes the system to be inefficient. Present systems do not allow the independent vacuum process of both the condenser and evaporator section of the system simultaneously.
Other common problems, in proper maintenance and repair of refrigeration systems, are the means to check the system to determine the location of leaks and the inability to perform repairs or other work on the condenser unit without "blowing the charge" or venting the charge into the atmosphere.
The prior art contains a number of teachings of servicing tools and/or means to provide access to a closed refrigeration system, e.g., those disclosed in U.S. Pat. No. 3,935,713 issued to John W. Olson, U.S. Pat. No. 3,916,947 issued to Paul M. Holmes, U.S. Pat. No. 3,785,163 issued to William Wagner, U.S. Pat. Nos. 3,916,641 and 3,996,765 issued to John W. Mullins.
The invention of Olson discloses an external tool for the removal of Schrader type (depressing) valves; it is not installed in the system; it does not have a main flow shut off valve and it does not contain a by pass mechanism to gain access to the system.
The invention of Holmes has an access port with a Schrader valve, which this invention (the "Hubble-Double Valve") eliminates. It does not have a shut off valve on the access port. The valve access is not upstream of the main shut off valve and, therefore, a technician cannot isolate the refrigerant upstream of the main shut off valve to perform a by pass operation. It only has one shut off valve in the refrigerant flow line.
The invention of Wagner provides a refrigerant charging means and method for charging a saturated vapor refrigerant into the low pressure side of a refrigeration or air conditioning system. It discloses a portable external device which is not installed in the system, either at the factory or on-site at the location of the unit. It is a method of metering the charge. It does not allow a by pass operation and does not allow the isolation of the evaporator or condenser sections of the systems in order that the location of leaks may be more easily ascertained.
The inventions of Mullins disclose a spring and cam shaft to depress a valve core, a Schrader valve which is eliminated by the "Hubbell-Double Valve" disclosed herein. The Mullins invention discloses a portable external tool or device which is not in the unit system and which does not have a double valve that allows a by pass operation.
This invention, the "Hubbell Double Valve", addresses and solves the above mentioned problems, when used with the prescribed techniques, and provides other advantages over present means which will be further discussed hereinafter.